class_docstr: Abstract class for a node in a Ray task graph.
  
  A node has a type (e.g., FunctionNode), data (e.g., function options and
  body), arguments (Python values, DAGNodes, and DAGNodes nested within Python
  argument values) and options (Ray API .options() used for function, class
  or class method)
docstr: Execute this node, assuming args have been transformed already.
docstr_tok: ["Execute","this","node",",","assuming","args","have","been","transformed","already","."]
code: def _execute_impl(
      self, *args, **kwargs
  ) -> Union[ray.ObjectRef, "ray.actor.ActorHandle"]:
      """Execute this node, assuming args have been transformed already."""
      raise NotImplementedError
  
imports: import ray
  from ray.dag.base import DAGNodeBase
  from ray.dag.py_obj_scanner import _PyObjScanner
  from ray.util.annotations import DeveloperAPI
  from typing import Optional, Union, List, Tuple, Dict, Any, TypeVar, Callable
  import uuid
  import asyncio
  from ray.dag.compiled_dag_node import build_compiled_dag_from_ray_dag
label_desc: Use image node_id 15 for calling the DAGNode obj's underlying member method code with example usage: obj._execute_impl() without return types